Domestic tobaccos such as burley, Maryland, flue-cured, bright leaf and Virginia tobaccos have less perceived flavor and aroma under smoking conditions than the Oriental or aromatic tobaccos which are imported into the United States from regions such as Turkey, Greece, Bulgaria and Abinol is a di-unsaturated labdanoid diterpene alcohol which is found in the cuticular wax of the Oriental type of tobacco leaf: ##STR2##
Oriental green leaf contains abienol, but there is no evidence of abienol after the leaf is sun-cured. Tobacco trichomes are the source of the abienol, and there is a thin film of abienol on the green leaf which is exposed to sunlight and air during curing. It appears that abienol is converted by photo-oxidative degradation, and generates the derivatives which provide the characteristic woody note of Oriental tobacco.
I. Wahlberg et al., in Acta Chem. Scand., B32, 203(1978) and B33, 437(1979) describe the chemistry of abienol photo-oxidation. Many of the photo-oxidation products obtained were identical to those found in sun-cured Oriental tobacco.
Among the abienol-derived constituents of sun-cured Oriental tobacco is sclareclide (norambreinolide)(I), which is structurally related to sclaral(II): ##STR3##
U.S. Pat. No. 2,978,365 describes domestic tobacco compositions which contain sclaral as a flavorant additive. The additive imparts a cedar-like flavor and aroma to the main stream and side stream smoke of tobacco products under smoking conditions.
There is continuing interest in the development of improved low delivery smoking compositions which generate mainstream smoke with flavorant-enhanced taste and character under smoking conditions.
Accordingly, it is an object of this invention to provide smoking compositions having incorporated therein a flavorant component which is characterized by lack of mobility and/or volatility at ambient temperature.
It is another object of this invention to provide smoking tobacco compositions having incorporated therein a flavorant composition which under normal smoking conditions imparts an improved flavor to mainstream smoke and an improved aroma to sidestream smoke.
It is a further object of this invention to provide novel abienol-related compounds which are adapted to be incorporated into tobacco compositions, and which under normal smoking conditions are released as volatile flavorants into cigarette smoke.
Other objects and advantages of the present invention shall become apparent from the following description and examples.